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OC'ing a Brisbane

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Last response: in CPUs
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November 13, 2008 5:42:27 PM

Hi Guys.

I got this CPU I want to give one more year (or two) of gaming life.
It is a AMD 4800+ X2 at 2.4Ghz G3 Stepping.
I know ive posted this on the Overclocking forum, but seems nobody seemed to have a opinion.
So, im posting here, where ive posted many times aswell.

At stock values the Core Temp (HWMonitor) is 22-25º under load.
At 2.9Ghz it hits the 28º. No voltage was messed up. Still at 1.328v.

I read around the web this cpu can go at 3.2Ghz with no problem. Mine seems pretty stable so far.
Ive read one review that took him at 3.5Ghz, but they refered it was stable, but it could burn up any minute.

I have the following rig:

Athlon 4800+ X2 2.5Ghz G2 Stepping
Asus A2M-VM
4 GB DDR2 533Mhz
ATI 4850 512Ram with aftermarket cooler.
Asus Triton 70 (cooler)
Corsair TX750

A CPUz validation link:
http://valid.x86-secret.com/show_oc.php?id=445909

I know it is not your legendaries Core cpus, but hey, I only overclocked when the machines were getting a bit outdated.
That is what im doing now. Im just tmapering with the HTT because honestly i have 533mhz rams and i want them that way.

3dmark scores:

Stock :8200
At 2.9Ghz:9700

I ask help to you guys if anybody had experience with these kinds of CPUs. Thank you.

PS: Going to start my testing now at 3Ghz.

More about : ing brisbane

November 13, 2008 6:42:53 PM

Prime started giving errors at 3Ghz. 3dmark results were also a bit lower.
Bumping voltage up to 1.345.

When it is stable, ill post a CPUz Validation link !!! If i get 3Ghz stable ill be glad, it is a 500Mhz/20% OC. I would love to reach 3.2Ghz but i dont think it would be possible. Lets see !!!

Again, any feedback over the voltages would be nice. I don't want to burn my mobo and CPU. Thanks in advance.
November 13, 2008 7:07:18 PM

Well, everybody seems to be sleeping atm.

Stable at 3ghz. Prime and 3dmark06 ok. In 3dmark i got 9800. Not bad :) 

Temp reached 33º under full Prime load. Ill head for the magic 3.2Ghz now. If anybody has something to add, please do.
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November 13, 2008 7:37:25 PM

Alright. Last post.

I can get past the 3Ghz mark i think it is my ram. Altering the Voltage didn't make it POST. They are 533Mhz ram.
Oh well. With a crappy board, and crappy ram, a 500mhz/20% OC doesn't seem too shabby.

See ya around folks, and time for the CPUz Validator.

http://valid.x86-secret.com/show_oc.php?id=445965

Here it is. Oh well, back to gaming !! See ya !!
a c 866 à CPUs
November 13, 2008 7:54:26 PM

Change your ht link to 4x it might allow you to go higher to keep it around a 1000 on fsb speed, stability issues increase after 1100.
November 13, 2008 9:11:58 PM

rolli59 said:
Change your ht link to 4x it might allow you to go higher to keep it around a 1000 on fsb speed, stability issues increase after 1100.


ill try it tomorrow thanks. its is quite above that value now.
November 13, 2008 9:58:45 PM

Thank you for the Tip rolli, but i sense i am facing a brick wall.

Probably because it is a crappy mobo, and crappy ram. Can push it to 3050mhz, but not further. It wont post most times.
LDT bus ( their name for HT) being at whatever frequency wont work.

Anyway, even with a crappy setup i was able to get a nice OC. Thank you for the tips. And OC those brisbanes at home people !!!! At least mine seemed pretty nice.
a c 111 à CPUs
November 13, 2008 10:23:43 PM

I don't know what your cpu voltage and temps are now but 33c @ 1.328v is really good if you are approaching 3GHz.

Dropping the HT to x4 will not effect your overall performance. You should be able to go 1.375v but I'm not real familiar with that stepping - I think some folks have gone well over 1.4v but I try to stay under that voltage.

You should know when you 'hit the wall' with the cpu. With the Brisbanes your volts/temps will get out of control with little GHz in return.

Mixing your memory is holding you back, too, though the 4-4-4-12 timings are great. You are leaving some performance on the table overall because of your low ram speed.

At a 250MHz clock you will be over 3.1GHz with your HT at 1000MHz (x4). If you stick with the PC2-6400 at the '333MHz' ratio your overall ram speed will approach 750MHz - the memory divisor for the X2 4800+ is ""7"".

250MHz x 12.5 = 3125MHz / 7 = 446 x .8325 (333MHz ratio) = 373 x 2 or 746MHz ram speed.

To hit 3.2 ...

256MHz x 12.5 = 3200MHz / 7 = 457MHz x .8325 = 381 x 2 or 761MHz ram speed
(your HT @ x4 will be 1024MHz - you could drop back to x3 @ 768MHz - still faster than your ram speed)
!